1. Field of the Invention
The present invention relates to a calibration camera device which can be used in geometrical correction in combination with color correction by itself and particularly to a calibration camera device which is preferably used in image quality control of an image displaying device.
2. Description of the Related Art
Conventionally, an image displaying device has been proposed wherein a plurality of images are projected from the corresponding projectors and synthesized as one large image on one screen. At each projector, however, may occur geometrical distortion, color shading, luminance shading, difference in gamma characteristic, difference in white balance and the like. In this case, the differences in image quality between the projectors become conspicuous, thereby deteriorating the displaying quality of the image displaying device. In this point of view, an image displaying device is proposed wherein a camera is provided in front of the screen, and a test pattern displayed on the screen is captured, and correction data is calculated on the captured image, and the input image is corrected on the correction data and output, thereby conducting geometrical correction, color correction and luminance correction (see, Patent publication No. 1).
Among the above-mentioned corrections, the color correction is often conducted by means of a color measuring device or the like. Since the color measuring device is expensive and is required to be set at every point if in the color correction, there are a plurality of photometric points, however, the cost in the color correction may be increased and the operationality in the color correction may be complicated. In order to iron out this problem, a two-dimensional color measuring device is proposed wherein the color correction can be conducted simultaneously for the plurality of photometric points (see, Patent publication No. 2). In the use of the two-dimensional color measuring device, the operation to set the measuring device to the plurality of photometric points can be mitigated.    [Patent publication No. 1] Japanese Patent Application Laid-open No. 9-326981    [Patent publication No. 2] Japanese Patent Publication No. 3246021
The two dimensional color measuring device disclosed in Patent Publication No. 2 is so configured as to install, in an capturing device (camera), an optical filter made of a relatively expensive interference filter (e.g., made of glass) close to the color matching functions of a given three-dimensional displaying color system. Therefore, the total cost of the two dimensional color measuring device is increased because the parts cost is increased due to the use of the interference filter and the operationality becomes complicated due to the precise attachment of the optical filter in the capturing device. Then, if the geometrical correction and the color correction are conducted simultaneously, another capturing device (camera) for the geometrical correction must be provided in addition to the capturing device for the color correction, so that the setting cost and the setting space of the capturing devices may be increased and the setting period of time of the capturing devices may be elongated.